Stabilized radio rescue beacon

ABSTRACT

1,072,883. Radio rescue buoys. BURNDEPT ELECTRONICS Ltd. Nov. 26, 1965 [Nov. 27, 1964], No. 48440/64. Heading B7A. [Also in Division H4] A radio rescue beacon comprises a cylindrical buoy 10 having a rod aerial 30 projecting from its upper end plate 13, said aerial being mounted on a pivoted spring-loaded baseplate 32 so that it may be swung down alongside the buoy and be secured for stowing. The upper part 12 of the buoy 10 is watertight and contains the electronio components of a transistor transmitterreceiver and the lower part 18 contains a battery, which may be sea water-activated. A switch 38 operated by the baseplate 32 upon stowage of the aerial disconnects the battery, and in a similar way connection is made to the input/output terminal of the transmitterreceiver when the aerial is elevated. A pair of spring-loaded sheet metal paddles 40, 41, which are pivotally mounted on the buoy, are folded down for stowage, but project outwards when released, under the control of biasing springs 48, Fig. 3 (not shown). The said paddles provide stabilization for the buoy, downward movements of which in the water are strongly resisted, the paddles being fully opened with their inner edges firmly against the buoy, whereas upward movements are but little resisted, the paddles closing against the springs 48. A towing cord 52, Fig. 1, extending from a bridle 54, is used to lash the paddles 40, 41 and the aerial 30 to the buoy 10 for stowage, any surplus is taken up in a suitable reel, and it is then secured by a water-soluble fastening. The aerial 30 may have a flexible extension 31, Fig. 2 (not shown). In a second embodiment, three circular paddle blades 60, 61, 62, Fig. 4 (not shown), are mounted on the bottom closure 19 of the buoy and are arranged to fold inwards, by rotation on vertical axes, for stowing. In a third embodiment, an annular space is formed around the lower end of the buoy by an outer casing 100, Figs. 5, 6 (not shown), which is open at the bottom but is closed at the top except for a number of vents 102, outside which are downwardly directed ducts 104.

March 10, 1970 a, w, FLETCHER ETAL 3,500,209

STABILIZED RADIO RESCUE BEACON 4 Sheets-Sheet 1 Filed Nov. 24, 1965five-vitam- 6. W. FZe cZI P 5 March 10, 1970 s, w. FLETCHER ErAL3,500,209

STABILIZED RADIO RESCUE BEACON Filed Nov. 24. 1965 4 Sheets-Sheet 2 Ivawims WFZe'Zclle# K. W. Lee-Ke777p March 10, 1970 3, w, FLETCHER ETAL3,500,209

STABILIZED RADIO RESCUE BEACON Filed NOV. 24, 1965 I 4 Sheets-Sheet 3 InvenZ o/w FZeTcZar K W. Lce-Ke771p March 10, 1970 s. w. FLETCHER EI'AL3,500,209

STABILIZED RADIO RESCUE BEACON 4 Sheets-$heet 4 Filed Nov. 24, 1965frn/Qfii'ohs W FZeCclLer 1 WM 2 m 3 M K v B United States Patent3,500,209 STABILIZED RADIO RESCUE BEACON Gordon William Fletcher andKenneth William Lee- Kemp, both of Riversite Works, Erith, Kent, EnglandFiled Nov. 24, 1965, Ser. No. 509,529 Claims priority, application GreatBritain, Nov. 27, 1964, 48,440/ 64 Int. Cl. H04b 1/02 US. Cl. 325-116 6Claims ABSTRACT OF THE DISCLOSURE A buoyant radio rescue beacon having abattery with a transmitter powered thereby, with the transmitter andbattery housed in an elongated buoy, forming a part of the beacon and asubstantially rigid antenna mounted to project from the buoy. The bodyof the buoy is provided with stabilizing means comprising at least twopaddles which are adapted to swing outwardly from the body of the buoyto full open position when the buoy falls in the water.

In a beacon in accordance with the invention the conventional springleaf aerial is replaced by a substantially rigid aerial pivotallymounted on the beacon buoy, preferably at or near what will in use bethe uppermost part of the outer surface of the buoy, to lie alongsidethe buoy in a stowed position when the beacon is not in use andspring-loaded to project upwards from the buoy when released, as by theaction of water on some water soluble fastening.

If the length of aerial required is such that a wholly rigid aerialwould project beyond the buoy in its stowed position the outer lengthmay be made of flexible material and folded.

The need for stabilisation of the buoy is preferably met in a beacon inaccordance with the invention by the provision of paddles pivotallymounted on the buoy to swing about an axis which will be generallyhorizontal when the buoy is floating normally, and which can swingtowards a closed position alongside the buoy as it rises through thewater and to a fully open position projecting from the buoy as it falls.An alternative stabilizer is described below.

Preferably the paddles are urged by springs towards the open position.They can conveniently be held in the closed, stowed position by the samefastening which is used to hold down the aerial.

In order that the invention may be more thoroughly understood threeradio rescue beacons in accordance with it will be described in somedetail, by way of example, with reference to the accompanying drawings,in which:

FIGURE 1 is an isometric view of one beacon with part broken away;

FIGURE 2 is an elevation of the same, showing the aerial in the stowedposition;

FIGURE 3 is a detail cross-section showing the mounting of the paddles;

FIGURE 4 is a view from the lower end of a second beacon with circularstabilizing paddles on the lower end closure;

FIGURE 5 is an isometric view of a third beacon stabilized by an outercasing around the battery compartment; and

FIGURE 6 is a detail cross-section of the same.

The battery and the electronic components of the beacon shown in FIGURES1 to 3 are enclosed in a cylindrical buoy 10. The buoy 10 is made in twoparts. The upper part 12, comprising some two thirds of the length,houses the electronic components of a transistor transmitter-receiver,part visible at 14. The remaining space is packed with expandedpolystyrene, seen at 16, to maintain buoyancy even in the event ofdamage to the outer skin of the cylinder. The lower part 18 of the buoy12 forms a compartment 20 to house the battery (not shown), and so thata sea water-activated battery may be used if required the two parts areisolated from one another by a metal sealing plate 22, the leads 24 fromthe battery passing through glands 26, 28, in this plate.

The effect of the weight of the battery in the lower compartment 20 isto ballast the buoy 10, when it is afioat toward an upright position.

The aerial 30 is mounted on the upper end plate 13 of the cylindricalbuoy 10 to swing out from a stowed position alongside the buoy to anoperating position in which it projects from the upper end face of thebuoy and is nearly coaxial with the buoy. For this purpose the aerial ismounted on a metal base plate 32 pivotally mounted about a shaft 34parallel to the end surface of the buoy and is urged toward theoperating position (FIGURE 1) by a helical spring 36 secured to theshaft. The shaft 34 is carried between two lugs on a plate 33 ecured toa slab 35 of insulating material such as polytetrafluorethylene. Theslab is in turn secured to the end plate 13.

The slab 35 serves to insulate the plate 33 electrically from the bodyof the beacon buoy 10. A connector pin (not shown) projects from theplate33 through registering openings in the slab 35 and the end plate 13to receive a connection from the coaxial cable 29 from the beaconoutput. The opening in the end plate 13 is sealed with an O-ring.

In the stowed position of the aerial (FIGURE 2) its base plate 32appears against plunger 38 which opens a switch (not shown) in the powersupply by way of the lead 39.

The aerial itself is in the form of a metal tube about a quarter of aninch in diameter and suitably plated to resist corrosion. The particularbeacon described is housed in a buoy some twenty four inches long andfor the required operating frequencies the aerial has to be about thirtyinches long. So that it need not project beyond the buoy in the stowedposition the last six inches or so (31) are of resilient wire and can befolded alongside the buoy.

The buoy 10 is stabilised by a pair of sheet metal paddles 40, 41mounted diametrically opposite to one another at the level of thesealing plate 22 between the two parts at the inner end of the batterycompartment 20.

The paddles are each about five inches long and they are curved about alongitudinal axis to the same curvature as that of the cylindrical buoy,in this particular example to a radius of some two and a quarter inches,tapering from an overall width of four and a half inches from asemicircular root to some three inches at the tip.

The paddles are each mounted on the sealing plate between the two partsof the buoy to swing about a transverse shaft 42 or 43 running acrossthe root, more or less on the diameter of the semicircle, between twotabs 44, 44 or 45, 45' formed at the root of paddle. The paddles aremounted to swing upwards and out from a stowed 3 position closealongside the buoy until in the fully eX- tended position the roots abutthe wall of the buoy with the paddles projecting at an angle of about 45to 50 degrees to the axis of the buoy.

The sealing plate 22 has a downwardly extending annular flange 23 andthis carries a diametrically opposed pair of plane edged projections 46,47 which project from the buoy to provide bearing surfaces for thepaddles. The shafts 42, 43 are received through opposed pairs of holespassing through the projections 46, 47 and the flange 23 on the sealingplate 22 form the bearing surfaces and a helical spring, one of which isshown at 48, is secured to a collar 50 on each shaft and is wound up tourge the paddle to the extended position.

These paddles have been found to display a very marked stabilizingeffect upon the buoy. As the buoy rises on the crest of a wave they folddown towards the retracted position and offer little resistance, and asit starts to fall in a trough they open out again to resist the fall.The buoy as it were climbs out of the water. They also substantiallyreduce the tendency of the buoy to roll from side to side.

More than two paddles can be used with improved stabilisation at theexpense of design complication.

The sealing plate 22 which forms the upper end wall of the batterycompartment 20 engages an O ring seal 51 fitted in an annular groove inan lower end plate 53 of the upper part 12 of the buoy. The two parts ofthe buoy are secured together by six screws, two of which appear at 55,disposed outside the O ring seal. The screws 55 can be manipulated fromthe lower end of the battery compartment 20 before the battery isinserted and the lower end closure 19 secured in place.

The buoy is fitted with a towing cord 52 and this cord is used to holdboth aerial and paddles in the stowed position when the beacon is not inuse. The cord is coiled around the buoy, as shown in FIGURE 2, and heldin place by a water-soluble fastening (not shown). Upon immersion thecord 52 is released to unwind from around the buoy thus in turnreleasing first the aerial 30 and then the two paddles 40, 41. The cordis secured to the buoy by a bridle 54 between a top ring 56 and a ring58 on the battery compartment 18 for stability when being towed throughthe water.

It would be an advantage if more paddles could be provided around theperiphery of the floating beacon, since this would improve thestability, particularly as regards the rocking movement about the pointof buoyancy. An example of a three-bladed stabilizer is illustrated inFIG- URE 4. In this example the paddle blades 60, 61 and 62 are ofcircular form and are mounted at the bottom of the battery compartment18, on the bottom closure 19. In the closed position the circular bladeslie within the circumference of the buoy, but on activation they areswung out in the plane of the bottom closure by coil springs (not shown)around the shafts 64, 65, and 66 by which each blade is mounted to pivotabout a point close to its circumference.

The blades 60, 61 and 62 are not only spring loaded so as to rotateabout their pivot points to provide a clover leaf pattern, but also, bycoil springs 68, 69 and 70 to open and close as the beacon falls intothe troughs and rises onto the crests of the waves.

An alternative manner of stabilisation, illustrated in FIGURES and 6, isto fit an outer casing 100 around the battery compartment 18, theannular space thus formed being open at its outer and lower end andclosed at its inner and upper end except for a number of discreteopenings 102 ducted down toward the lower end by deflector cowls 104.Air trapped in the annulas and downwardly ejected sea water from thecowls 104 has a similar stabilising effect to that of paddles.

If the length of the cord 52 is too great for it to be convenient tocoil the cord around the buoy, as shown in FIGURE 2, a convenientalternative arrangement is to fit a reel, coaxially on the body of thebeacon. For example, it has been found particularly convenient to deepenthe lower end plate 53 and to reduce the diameter of the lower end ofthe upper part 12 of the buoy and to fit the reel within the recess thusformed. The reel will have its outer circumference flush with thesurface of the buoy and the cord is guided through an eye carried on thesealing plate 22. It is also possible to fit the reel at the lower endof the buoy in a generally similar fashion. The reel can be maderemoveable so that the cord is paved out as the buoy floats away or thereel can be fixed to the buoy so that the cord is payed out from thebuoy.

If the cord is not wound around the paddles 40, 41 of the beacon shownin FIGURES 1-3, some other water soluble fastening must be used. Forexample, the paddles can be formed with complementary pair of tabs whichform the two halves of a spoon when the paddles are folded and the spoonfilled with water soluble binding material.

We claim:

1. A buoyant radio rescue beacon, comprising: a battery; a beacontransmitter powered by said battery; an elongated beacon buoy housingsaid battery and transmitter, a substantially rigid antenna, saidbattery and said antenna being at opposite ends of said buoy andstabilizing means comprising at least two paddles pivotally mounted nearthe lower end on said buoy to swing about an axis transverse to saidbuoy, and so as to swing towards a closed position alongside the buoy asthe same rises through water and to a fully open position projectingfrom the buoy as it falls.

2. A buoyant radio rescue beacon, comprising a battery; a beacontransmitter powered by said battery; an elongated beacon buoy, housingsaid battery and transmitter, a substantially rigid antenna, saidbattery and said antenna being at opposite ends of said buoy, andstabilizing means comprising at least two paddles pivotally mounted nearthe lower end on said buoy to swing about an axis transverse to saidbuoy, and so as to swing towards a closed position alongside the buoy asthe same rises through water and to a fully open position projectingfrom the buoy as it falls, and said paddles being urged by springstowards said open position.

3. A buoyant radio rescue beacon, comprising a battery; a beacontransmitter powered by said battery; an elongated beacon buoy, housingsaid battery and transmitter, a substantially rigid antenna, saidbattery and said antenna being at opposite ends of said buoy, andstabilizing means comprising at least two paddles pivotally mounted nearthe lower end on said buoy to swing about an axis transverse to saidbuoy, and so as to swing towards a closed position alongside the buoy asthe same rises through water and to a fully open position projectingfrom the buoy as it falls, said paddles being urged by springs towardsthe open position, and said paddles being mounted diametrically oppositeto one another on the side of said buoy, each to swing about atransverse axis upwards and outwards from the stowed position closealongside the buoy to a fully extended position in which said paddlesproject at an angle to the axis of the buoy.

4. A beacon in accordance with claim 3, wherein said buoy is cylindricaland paddles are curved about their longitudinal axes to substantiallythe same curvature as that of the cylindrical buoy.

5. A beacon in accordance with claim 3, wherein said paddles are mountedon the inner end of the part of said buoy wherein is housed saidbattery.

6. A beacon in accordance with claim 2, wherein said paddle blades aremounted at the outer end of the part of said buoy wherein is housed saidbattery, said blades being mounted to swing out from said stowedposition in which they lie substantially within the circumference of 6the buoy and spring-loaded to open and close as the 3,097,622 7/1963Bell 114-125 beacon falls into wave troughs and rises onto wave crests.3,132,322 5/ 1964 Mass 343880 X 3,281,765 10/1966 Taplin 340-2 Referencs Cited 3,290,642 12/1966 Mason et a1. 340-2 UNITED STATES PATENTS 5ROBERT L. GRIFFIN, Primary Examiner 2,310,017 2/1943 Canon 32 5-112 X3,253,810 5 /1966 Penn 325 1 1 X BENEDICT V. SAFOUREK, AssistantExaminer 935,717 10/1909 Williams 9-8 U S,C1 X R 2,928,935 3/1960 Murray325-416 X 3,006,002 10/1961 Pingree et a1. 98 10 325-119; MP2;

